The present claimed invention relates to fluid ejection devices. More specifically, the present claimed invention relates to generating multiple drops weights in a fluid ejection device.
As technology progresses, increased performance demands are placed on various components including printing systems. For example, modern printing systems may now handle many different print modes and/or various print media. Furthermore, each print mode and/or print media may use a particular drop weight in order to maximize efficiency of the printing process. That is, when in draft mode, or when operating in high throughput printing conditions, it may be desirable to eject higher weight ink drops from the firing chamber of the printhead. Conversely, photo printing or UIQ (ultimate image quality) printing may be performed more effectively by ejecting lower weight ink drops from the firing chamber of the printhead.
Moreover, UIQ printing is thought to exist only when drop weights are on the order of 1-2 nanograms thereby reaching the visual perception limits of the human eye. Draft mode printing, on the other hand, may typically operate efficiently with ink drop weights of at least 3-6 nanograms. As a result of such different drop weight requirements, a pen having a printhead designed for one type of printing mode or media is often not well suited for use with a separate and different type of printing mode or media.
As yet another concern, the printing mode may not be consistent throughout an entire print job. For example, on a single page it may be desirable to print a high quality image (e.g. a photographic image) on one portion of the page and print a lower quality image (e.g. a monochrome region) on another portion of the page. In such a case, a low drop weight printhead may be used to achieve the photo quality resolution of the photographic image, but such a low drop weight printhead may not be particularly efficient for printing the monochrome region. Thus, a particular printhead which is chosen for its ability to perform photo quality printing, may ultimately reduce the efficiency of an overall printing process.
Thus, a desire has arisen for drop weights that correspond to differing resolutions and that efficiently meet technological demands of sophisticated printing systems.
In one embodiment, the present invention recites a fluid ejection device comprising a first drop ejector associated with a firing chamber. The first drop ejector is configured to cause fluid having a first drop weight to be ejected from the firing chamber, wherein the first drop ejector includes a first heating element and first drive circuitry electrically coupled with the first heating element. The present embodiment further comprises a first bore disposed within an orifice layer disposed proximate the first drop ejector and associated with the first drop ejector. The present embodiment also comprises a second drop ejector associated with the firing chamber. The second drop ejector is configured to cause fluid having a second drop weight to be ejected from the firing chamber, wherein the second drop ejector includes a second heating element and second drive circuitry electrically coupled with the second heating element. The present embodiment further comprises a second bore disposed within the orifice layer disposed proximate the second drop ejector, and the second bore is associated with the second drop ejector.